NASA’s Double Asteroid Redirection Test, known as DART, did more than shove a small asteroid into a tighter loop around its ...

Four years ago, NASA purposely smashed a spacecraft into a small asteroid to see if they could deflect it—a test to prove humanity could protect Earth from threatening space rocks.

NASA’s DART mission precisely measured changes in asteroid Dimorphos’ orbit and the Didymos system’s heliocentric motion using radar, stellar occultations and space observations.

NASA officials warn thousands of undetected “city killer” asteroids may be circling near Earth. With limited deflection tools ready, are we prepared if one suddenly shifts onto a collision course?